Mass spectrometry imaging is a powerful technique that can be used to determine the distribution of specific biomolecules in tissue sections and their relative abundance, providing a mass-resolved image for each of the detected compounds. Currently, for imaging mass spectrometry, it is possible to obtain mass spectra of large biomolecules such as peptides and proteins using matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging at a spatial resolution of 5 to 200 μm.